marshall vintage modern?

[chuckb]

hey guys, i have a marshall vintage modern 2266 that i'm having trouble with. the amp powers on, tubes light up but i have no sound. i removed the chassis to have a look inside and one of the resistors(R67) are burnt looking,but can't tell what the value is (it looks like brown,green maybe yellow and gold)and if it has any effect on why i have no sound? anyone have a schematic for this amp?

[The Dude]

I couldn't find a schematic, but here's a link to a high res picture of the innards. Maybe you can identify the resistor from the pic?

http://cachepe.zzounds.com/media/qua...47defd8248.jpg

[oc disorder]

Here's 2 of them from Russia with Love..... 50w PSU & O/P ... Part of FX section

http://forum.guitarplayer.ru/index.p...;attach=293704

http://forum.guitarplayer.ru/index.p...;attach=293703

[g1]

There is also a R67 in the supply, feeding the D7 bias diode. I believe it is beside the bias trimpot in the photo The Dude posted.
It is 150K so that matches the description "looks like brown,green maybe yellow and gold".
If it is really burnt, there would be loss of bias and I would think fuse FS2 should blow, resulting in no sound.
Perhaps it is not really burnt? Check it's resistance on a meter with one leg disconnected. Can you post a pic?

[Chuck H]

That resistor shouldn't blow (or burn) under most circumstances. Even a power tube failure. I would sooner expect a different bias resistor to eat it.?. But I guess we've seen weirder. Do replace it and check the whole bias supply and it's output voltage. Possible power tube failure.?.